Plumbing and drainage part 1 - Water services

This Australian Standard specifies requirements for the design, installation and commissioning of cold water services from a point of connection to the points of discharge, non-drinking water from a point of connection to the points of discharge.

It applies to new installations as well as alterations, additions and repairs to existing installations.

This standard is to be read in conjunction with the Plumbing Code of Australia (PCA).

What's included

AS/NZS 3500.1:2021 contains eighteen sections:

• Section 1: states what the standard covers, describes the terms and abbreviations used in this Standard and states any exclusions.
• Section 2: specifies requirements for materials and products used in water services.
• Section 3: specifies requirements for the sizing of pipes for water service installations.
• Section 4: specifies requirements and methods for the prevention of contamination of the drinking water within the water service and the water main and provides for the selection and installation of backflow prevention devices.
• Section 5: specifies requirements for the installation of pipes, fittings, and apparatus used in cold water services.
• Section 6: specifies requirements for the installation of fire hydrants, fire hose reels, fire sprinkler services and independent wall drencher systems downstream of the backflow prevention device fitted, where required, to a water supply system.
• Section 7: sets out requirements for and defines the types of irrigation systems for the purposes of backflow prevention.
• Section 8: specifies requirements for water storage tanks.
• Section 9: specifies the design, installation, and maintenance requirements for non-drinking water services, including recycled and reclaimed water from the point of connection to the point of discharge.
• Section 10: specifies requirements for the installation of services for the supply of greywater, which has been treated, from a greywater treatment system to the point of re-use.
• Section 11: specifies requirements for water services used for sanitary flushing purposes.
• Section 12: specifies installation requirements for the connection of water supply to specified fixtures.
• Section 13: specifies requirements for the installation of pumps used in water services for buildings.
• Section 14: requirements for water services installed to supply haemodialysis machines.
• Section 15: specifies general requirements for the location, installation, electrical safety precautions and protection of property water meters.
• Section 16: specifies minimum requirements for the installation of a water supply system from a rainwater tank, where the tank is collecting water from roof catchments and is installed in an area where water from a network utility operator is provided to the property.
• Section 17: specifies minimum requirements for main lines of water services located within common property of a multi-unit development of 20 or more residential buildings up to three storeys in height.
• Section 18: specifies requirements for testing and commissioning a water service.

This Standard also contains four normative and five informative appendices:

• Appendix A provides tables for selecting the appropriate pipe nominal diameter (DN), based on internal diameter for different pipe materials and types, standard dimension ratios (SDRs) or pressure classes, as marked on the pipe. The equivalent pipe DN for different materials shall be determined using Tables A1, A2, A3, A4 and A5.
• Appendix B comprises a list of pipes and fittings are acceptable solutions.
• Appendix C contains a sizing method that may be used as an alternative to a full hydraulic calculation for the rapid sizing of piping, using the probable simultaneous demand (PSD) values.
• Appendix D comprises provides a method for sizing of piping for the supply of water to single or multiple dwellings and uses the probable simultaneous demand (PSD) values.
• Appendix E provides some examples of installations in which cross-connections are likely to be encountered.
• Appendix F provides examples for individual zone and containment protection together with hazard ratings and device selection.
• Appendix G contains an example of the calculations for inflow rate, overflow size, spill level air gap and height of inlet above invert of overflow for storage tanks.
• Appendix H sets out the cleaning and disinfection process of storage tanks.
• Appendix I sets out the process of disinfection of water services. 

This Standard is referenced in Part B1 Cold water services, Part B3 Non-drinking water services, Part B4 Fire-fighting water services, Part B5 Cross-connection control, and Part B6 Rainwater harvesting and use of the NCC Volume Three. It applies to water service requirements in all classes of building.